you all know i am a big fan of SRAM's DualDrive hub. the reasons are primarily two. one, for the gearing range our affords. two, for the uber-smooth and nearly instantaneous shifts across the three gear bands. recent riding with Shimano 105 5800, however, has been quite surprising about how effortlessly and accurately shifts are between chainrings. no clunk, no grating sound of the chain against the FD. quite impressive, actually. not quite as quick and crisp as SRAM DD, but very, very good. i may have to rethink my predilection. for it in the future. Kudos to Shimano for dialing it in.